This disclosure relates generally to online systems, and more specifically to selecting content to online system users to increase likelihood of users later recalling the content.
Online systems, such as social networking systems, allow users to connect to and to communicate with other users of the online system. Users may create profiles on an online system that are tied to their identities and include information about the users, such as interests and demographic information. The users may be individuals or entities such as corporations or charities. Online systems allow users to easily communicate and to share content with other online system users by providing content to an online system for presentation to other users. Content provided to an online system by a user may be declarative information provided by a user, status updates, check-ins to locations, images, photographs, videos, text data, or any other information a user wishes to share with additional users of the online system. An online system may also generate content for presentation to a user, such as content describing actions taken by other users on the online system.
Additionally, many online systems commonly allow users (e.g., businesses) to sponsor presentation of content on an online system to gain public attention for a user's products or services or to persuade other users to take an action regarding the user's products or services. Content for which the online system receives compensation in exchange for presenting to users is referred to as “sponsored content.” Many online systems receive compensation from a user for presenting online system users with certain types of sponsored content provided by the user. Frequently, online systems charge a user for each presentation of sponsored content to an online system user or for each interaction with sponsored content by an online system user. For example, an online system receives compensation from an entity each time a content item provided by the user is displayed to another user on the online system or each time another user is presented with a content item on the online system and interacts with the content item (e.g., selects a link included in the content item), or each time another user performs another action after being presented with the content item.
As a relatively limited number of users of an online system may frequently interact with sponsored content provided by the online system, competition for presenting sponsored content to those users may result in larger amounts of compensation to the online system, which limits the number of users capable of providing the amounts of compensation. However, other online system users may view sponsored content for long amounts of time, which increases likelihoods of the users subsequently recalling the sponsored content and taking an action. For example, a user may make a purchase from a business identified by sponsored content the user views for greater than a particular amount of time even if the user does not interact with the sponsored content while it is presented. While users sponsoring content presented by an online system may obtain benefits from sponsored content presented by the online system but with which online system users do not interact, conventional online systems select sponsored content for presentation to users based on likelihoods of interaction with sponsored content. This may limit the sponsored content presented by an online system.